摘要
作者采用拟合法、多次阻断技术,压力-容积环(PV环)测量等观察麻醉犬油酸呼吸窘迫综合征(RDS)模型在0～4h的肺力学改变。结果:(1)顺应性降低,吸气相及呼气相的肺顺应性分别由对照值0.9942±0.3773,1.1706±0.4466降至0.4120±0.0714,0.3365±0.0398 L·kPa;跨肺压(Ptp)、气道压(Pao)升高;功能残气量(FRC)减少等改变主要发生于0～2h,其后2～4h期间的变化缓慢,且多未达显著水平。(2)拟合法测得呼气相的气流阻力显著升高,肺阻力及呼吸系统阻力分别由对照值-0.06±0.13,0.32±0.05增至4h时0.42±0.05,0.67±0.08kPa·L·s。(3)肺以及整个呼吸系统的压力-容积环(PV环)的变化趋势基本相同,主要有充气支出现拐点,位于0.98kPa处;环的滞后程度加大,注入油酸后4h,跨肺压-容积环及气道压-容积环的“半容积宽度”分别由注入前的0.36及0.69增为0.81及1.05kPa;环向下方移位。我们认为,在成人呼吸窘迫综合征(ARDS)通气支持治疗过程中,以选用拟合法结合PV环测量,根据Pao、呼吸流率等生理变化,实行肺力学变化的实时监测为宜。
In mechanically ventilated anesthetized dogs( pentobarbital sodium, 30 mg/kg) with acute lung injuries induced by intravenous oleic acid(OA), changes in airflow, lung volume, and trachcal(Pao), trarspulmonary (Ptp), csophageal( Pcs) pressures were measured. Changes in lung mechanics after OA injection were studied at intervals for 4 hours through parameter estimation, by curve fitting method and interrupter technique and with pressure-volume loops. The main findings were as follows: (1) Compliance, FRC showed a marked decrease, lung complaince at inspiratory and expiratory phases decreased from control values of 0.994 2 ±0.377 3 and 1.170 6± 0.4466 to 0.4120±0.0714 and 0.3365±0.0398 L·kPa 1, respectively. Pao and Ptp showed a marked increase after OA injection at 1-2 h intervals. (2) Airflow resistance at expiratory phase estimated by curve-fitting method showed a marked increase after OA injection. The resistance of lung and respiratory system increased from control values of-0.06±0.13 and 0.32± 0.05 to 0.42±0.05 and 0.67±0.08 kPa·L 1· s 4 h after OA infusion, respectively. ( 3) Pressure-volume loops of lung and total respiratory system showed similar changes 4 h after OA infusion, characterized by the presence of an inflexion point at the inflation limb, situated at 0.98 kPa, a marked increase in hysteresis and a rightward and downward shift of the loop. The 'half volume width' of Ptp-V and Pao-V increased from 0.36 and 0.69 to 0.81 and 1.05 kPa, respectively. It is suggested that the curve- fitting method in combi-nation with pressure-volume loop of total respiratory system would be more appropriate for lung mechanics monitoring during mechanical ventilatory support of ARDS patients.
出处
《第四军医大学学报》
1990年第4期278-284,共7页
Journal of the Fourth Military Medical University
关键词
成人
呼吸
窘迫综合征
肺力学
RDS
adult respiratory distress syndrome
lung mechanics
oleic acid
curve fitting method
interrupter technique
lung pressure - volume curve
respiratory system compliance
respiratory system airflow resistance
